Means for maintaining constant compression in cylinders of internalcombustion engines



March 14, 1950 G. HAWKINS MEANS FOR MAINTAINING CONSTANT COMPRESSION INCYLINDERS OF INTERNAL-COMBUSTION ENGINES Filed June 14, 1945Sheets-Sheet l 2.9 5 95" 3 V2; g x-25 2 E/ 6 Q Q 21 22 E '5 I9 P1 0 V 25I0 9 Q;

Q; 2 I H i i INVENTOR.

GRcvER H w\ \MS A'ITD R N EYS 2 Sheets-Sheet 2 March 14, 1950 G. HAWKINSMEANS FOR MAINTAINING CONSTANT COMPRESSION IN CYLINDERS OFINTERNAL-COMBUSTION ENGINES Flled June 14, 1945 IN 1w TOR.

ATTD RN EYS Patented Marl 14,

MEANS FOR MAINTAINING CONSTANT COM- PRESSION IN CYLINDERS OF INTERNAL-COMBUSTION ENGINES Grover Hawk ins, Shoshoni, Wyo. Application June14,1945, Serial No. 599,382

1 Claim. (Cl. 1 23-78) My present invention, in its broad aspect, has todo with improvements in means for maintaining a more or less constantcompression in cylinders of internal combustion engines, and

, especially two and four cycle engines of the auto type, wherebytendency to knock .is reduced, greater efliciency obtained at lowthrottle, and greater torque at fullthrottle, and whereby a very smallresidue of burned gases remain in a cylinder at the beginning of theintake stroke, hence a lower temperature is maintained on compressionand a considerable saving efiected in fuel consumed. v

In accomplishing the above and other results and advantages, I provide apressure equalizing chamber communicating through a conduit and valvewith the cylinder of the engine, and also communicating through a portwith a cylinder having a pressure responsive free piston, and whichcylinder also communicates with the cylinder of the engine, so thatchanges in compression (rise and fall of pressure) in the cylinder ofthe engine influence the movement of the free piston to regulate both thcompression in the cylinder of the engine and in the pressure equalizingchamber, and open and close the port between the pressure equalizingchamber and the cylinder of the pressure responsive free piston.

Other and equally important objects and advantages of my invention willbe apparent from the following description and drawings, and it ispointed out that changes in form, size, shape, materials, andconstruction and arrangement of parts are permissible and within thepurview of my broad inventive concept, and the scope of the appendedclaim.

In the drawings, wherein I have illustrated a preferred form of myinvention:

Figure 1 is a vertical section through my invention;

Figure 2 is a section on the line 22 of Figure 1;

Figure 3 is a section on the line 3-3 of Figure 2, and

Figure 4 is an enlarged vertical sectional view of the valve shown inFigure 1.

In the drawings, wherein like characters of reference are used todesignate like or similar parts:

The numeral l designates the cylinder of a conventional internalcombustion engine, and 2 the piston. The head 3 of the cylinder ismodified in accordance with my invention and has water circulationchannels 4 for cooling intake and exhaust valves 5 and 5A, and a sparkplug Bsee Figures 2 and 3. The head 3 carries a small cylinder 1communicating through the restricted open base 8 with the main cylinderl-such restricted base forming an annular shoulder 9 which has a springvalve ID to cover the ports 9a opening into the cylinder I. The use ofthe ports will make the total area of the piston l1 effective ratherthan just thehead l9, and a head II. The head II is flanged, as at I2,for attachment to the flange M at the tcp of the cylinder, and is formedwith a depending dome shaped extension I5 within the cylinder and hav--ing a rounded end It. A free piston I I having a skirt l8 and a head (9is mounted for movement in the cylinder I, and the head is provided withan extension fitting in the restricted base 8. The trapped air betweenthe head and skirt portions of piston l1 and the extension l5 and head Il cushions the upward stroke of the piston, and trapped air between theshoulder 9 and head l9 cushions the downward stroke oi the piston.

At a point near the limit of the upward stroke of the piston H, thecylinder 1 is provided with a port 20 communicating with a pressureequalizing tank or chamber 2 I, which also communicates through aconduit 22 with the top of cylinder i; there is an adjustable valve 23interpolated in the conduit 22. The valve 23 is of the automatic type,and has a cylinder 24 and a piston 25, a connection 26 leads gases underpressure from the main cylinder I and has branches 26A at oppositepoints of the piston 25. Movement of the piston is responsive topressure beneath it so that gas is transmitted to the compressionchamber until a predetermined pressure is reached, whereupon the piston25 moves to close the connection 26A against the pressure of spring 2!which is adjusted by thescrew 28 and cup 29 against which the spring 21bears. In operation when starting the engine cold, there would be nopressure in tank 2i, so at the first compression stroke, free piston llwould be forced up to the top of its cylinder, and would stay there.Thus the engine would function as a conventional gas engine.

.With no pressure in 2i and conduit 22, valve 25 would rest at thebottom of its cylinder under pressure of spring 21, and ports 26a wouldbe open into the annular space in the valve 25 and by the ports thereinto the under side of valve 25, directly through conduit 22 to tank 2|.

At the compression stroke, a small amount of air will pass through, andafter the explosion, more of the now burned gases will rush through.After a few minutes running, the desired pres- 3 sure as regulated byadjusting screw 28 will be reached in 2|, at this point valve 25 willhave reached the closed position shown, cutting ofl ports 26:: andpreventing further admission 01' air or gas. It pressure falls in 2| and22, spring 21 will push valve 25 down, admitting more gases, thusmaintaining a constant pressure in tank 2|.

Hence, as piston 2 comes up on compression. free piston I! will notbegin to rise until pressure above piston 2 is a little above that in2|.

Thus, as the piston 2 comes up on the compression stroke, the piston |1rises until the pressure above the piston I! is a little above thepressure in tank in chamber 2|, and by reason of valve 23 pressures willalso rise in tank or chamber 2| until all pressures are substantiallyequalized. Upon the firing of cylinder I, piston I! will be drivenhigher in cylinder 1 to close port 20. As piston 2 descends on the powerstroke, pressure in cylinder falls below that in tank 2|, and piston |1descends maintaininga substantially constant pressure in cylinder untilit reaches the bottom of its stroke.

The depending dome of the head of cylinder 1 is so designed to fitsnugly down in free piston H, thus reducing clearance, and increasingthe cushionin efiect. With a fiat head, the skirts of H would hammeragainst it. When the engine is throttled, piston |1 will only rise partway up in its cylinder; when the: explosion occurs, it will be driven upwith considerable force, and so this piston must be cushioned asdescribed.

From the foregoing it is believed that the operation and advantages ofmy invention will be apparent, but it is again emphasized thatinterpretation of its scope should only be conclusive when made in thelight of the subloined claim.

I claim:

Means for maintaining a constant compression in a cylinder of aninternal combustion engine, comprising a pressure equalizing tank havingan adjustable valved communication with the cylinder to receive gasestherefrom to a predeter- 4 mined pressure in the tank, said adjustablevalved communication including a. conduit, a valve having a pressureresponsive piston controlling passage of gases through the valve, aspring against which the valve operates and means for adjusting thetension of the spring on the valve, a cylinder communicating with thecylinder of the engine and having a port communicating with the pressuretank, a free piston in the cylinder responsive to pressures in the tankand the engine cylinder, and opening and closing the port at points inits stroke whereby to be moved down by pressure in the tank and moved upby pressure in the engine cylinder, said free pressure responsive pistonhaving a head and a skirt, the skirt opening and closing the port, andthe cylinder of the free piston having a head with a depending domebetween which and the piston air is trapped to cushion the upward strokeof the piston and air annular shoulder at the lower end of the cylinderbetween which and the piston air is trapped to cushion the downwardstroke of the piston relatively spaced ports in said shoulder and aspring valve adapted to control the ports to balance the piston duringdownward stroke thereof.

GROVER HAWKINS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,415,025 Folsom May 9, 19221,817,747 Hartley Aug. 4, 1931 FOREIGN PATENTS Number Country Date 4,281France Nov. 30, 1905 467,960 France June 25, 1914 176,233 Great BritainMar. 9, 1922 557,969 France Aug. 20, 1923

